import {
  LinearFilter,
  Mesh,
  OrthographicCamera,
  PerspectiveCamera,
  PlaneGeometry,
  RGBFormat,
  Scene,
  ShaderMaterial,
  UniformsUtils,
  WebGLRenderTarget
} from '../../three.module.js';

import {BokehDepthShader, BokehShader} from '../shaders/BokehShader2.js';

class CinematicCamera extends PerspectiveCamera {

  constructor(fov, aspect, near, far) {

    super(fov, aspect, near, far);

    this.type = 'CinematicCamera';

    this.postprocessing = {enabled: true};
    this.shaderSettings = {
      rings: 3,
      samples: 4
    };

    const depthShader = BokehDepthShader;

    this.materialDepth = new ShaderMaterial({
      uniforms: depthShader.uniforms,
      vertexShader: depthShader.vertexShader,
      fragmentShader: depthShader.fragmentShader
    });

    this.materialDepth.uniforms['mNear'].value = near;
    this.materialDepth.uniforms['mFar'].value = far;

    // In case of cinematicCamera, having a default lens set is important
    this.setLens();

    this.initPostProcessing();

  }

  // providing fnumber and coc(Circle of Confusion) as extra arguments
  // In case of cinematicCamera, having a default lens set is important
  // if fnumber and coc are not provided, cinematicCamera tries to act as a basic PerspectiveCamera
  setLens(focalLength = 35, filmGauge = 35, fNumber = 8, coc = 0.019) {

    this.filmGauge = filmGauge;

    this.setFocalLength(focalLength);

    this.fNumber = fNumber;
    this.coc = coc;

    // fNumber is focalLength by aperture
    this.aperture = focalLength / this.fNumber;

    // hyperFocal is required to calculate depthOfField when a lens tries to focus at a distance with given fNumber and focalLength
    this.hyperFocal = (focalLength * focalLength) / (this.aperture * this.coc);

  }

  linearize(depth) {

    const zfar = this.far;
    const znear = this.near;
    return -zfar * znear / (depth * (zfar - znear) - zfar);

  }

  smoothstep(near, far, depth) {

    const x = this.saturate((depth - near) / (far - near));
    return x * x * (3 - 2 * x);

  }

  saturate(x) {

    return Math.max(0, Math.min(1, x));

  }

  // function for focusing at a distance from the camera
  focusAt(focusDistance = 20) {

    const focalLength = this.getFocalLength();

    // distance from the camera (normal to frustrum) to focus on
    this.focus = focusDistance;

    // the nearest point from the camera which is in focus (unused)
    this.nearPoint = (this.hyperFocal * this.focus) / (this.hyperFocal + (this.focus - focalLength));

    // the farthest point from the camera which is in focus (unused)
    this.farPoint = (this.hyperFocal * this.focus) / (this.hyperFocal - (this.focus - focalLength));

    // the gap or width of the space in which is everything is in focus (unused)
    this.depthOfField = this.farPoint - this.nearPoint;

    // Considering minimum distance of focus for a standard lens (unused)
    if (this.depthOfField < 0) this.depthOfField = 0;

    this.sdistance = this.smoothstep(this.near, this.far, this.focus);

    this.ldistance = this.linearize(1 - this.sdistance);

    this.postprocessing.bokeh_uniforms['focalDepth'].value = this.ldistance;

  }

  initPostProcessing() {

    if (this.postprocessing.enabled) {

      this.postprocessing.scene = new Scene();

      this.postprocessing.camera = new OrthographicCamera(window.innerWidth / -2, window.innerWidth / 2, window.innerHeight / 2, window.innerHeight / -2, -10000, 10000);

      this.postprocessing.scene.add(this.postprocessing.camera);

      const pars = {minFilter: LinearFilter, magFilter: LinearFilter, format: RGBFormat};
      this.postprocessing.rtTextureDepth = new WebGLRenderTarget(window.innerWidth, window.innerHeight, pars);
      this.postprocessing.rtTextureColor = new WebGLRenderTarget(window.innerWidth, window.innerHeight, pars);

      const bokeh_shader = BokehShader;

      this.postprocessing.bokeh_uniforms = UniformsUtils.clone(bokeh_shader.uniforms);

      this.postprocessing.bokeh_uniforms['tColor'].value = this.postprocessing.rtTextureColor.texture;
      this.postprocessing.bokeh_uniforms['tDepth'].value = this.postprocessing.rtTextureDepth.texture;

      this.postprocessing.bokeh_uniforms['manualdof'].value = 0;
      this.postprocessing.bokeh_uniforms['shaderFocus'].value = 0;

      this.postprocessing.bokeh_uniforms['fstop'].value = 2.8;

      this.postprocessing.bokeh_uniforms['showFocus'].value = 1;

      this.postprocessing.bokeh_uniforms['focalDepth'].value = 0.1;

      //console.log( this.postprocessing.bokeh_uniforms[ "focalDepth" ].value );

      this.postprocessing.bokeh_uniforms['znear'].value = this.near;
      this.postprocessing.bokeh_uniforms['zfar'].value = this.near;


      this.postprocessing.bokeh_uniforms['textureWidth'].value = window.innerWidth;

      this.postprocessing.bokeh_uniforms['textureHeight'].value = window.innerHeight;

      this.postprocessing.materialBokeh = new ShaderMaterial({
        uniforms: this.postprocessing.bokeh_uniforms,
        vertexShader: bokeh_shader.vertexShader,
        fragmentShader: bokeh_shader.fragmentShader,
        defines: {
          RINGS: this.shaderSettings.rings,
          SAMPLES: this.shaderSettings.samples,
          DEPTH_PACKING: 1
        }
      });

      this.postprocessing.quad = new Mesh(new PlaneGeometry(window.innerWidth, window.innerHeight), this.postprocessing.materialBokeh);
      this.postprocessing.quad.position.z = -500;
      this.postprocessing.scene.add(this.postprocessing.quad);

    }

  }

  renderCinematic(scene, renderer) {

    if (this.postprocessing.enabled) {

      const currentRenderTarget = renderer.getRenderTarget();

      renderer.clear();

      // Render scene into texture

      scene.overrideMaterial = null;
      renderer.setRenderTarget(this.postprocessing.rtTextureColor);
      renderer.clear();
      renderer.render(scene, this);

      // Render depth into texture

      scene.overrideMaterial = this.materialDepth;
      renderer.setRenderTarget(this.postprocessing.rtTextureDepth);
      renderer.clear();
      renderer.render(scene, this);

      // Render bokeh composite

      renderer.setRenderTarget(null);
      renderer.render(this.postprocessing.scene, this.postprocessing.camera);

      renderer.setRenderTarget(currentRenderTarget);

    }

  }

}

export {CinematicCamera};
